Signal interferences of touch control terminals include liquid crystal display module (LCD module, LCM) interferences and common mode interferences. How to effectively overcome LCM interferences and common mode interferences is always a focus problem concerned by the industry.
At present, a usual method for avoiding LCM interferences in the industry is to add a shielding layer on a module. In the Chinese utility model patent application that has the application number of 201120048977.2 and is entitled as “Anti-interference LCM display structure”, by adding an anti-interference shielding layer, the anti-interference performance of the product is improved, and the service life of the product is further improved. However, the method of adding the shielding layer challenges the structure of the product, and is inconvenient for the product to develop towards the direction of miniaturization and thinness.
Furthermore, for avoiding common mode interferences, the main method of the current industry is to improve the circuit structure. In the Chinese invention patent application that has the application number of 201010146215.6 and is entitled as “Touch detection method and detection circuit for capacitive touch screen”, by improving the circuit structure, the anti-interference capability of a capacitive touch screen is improved. In this application, the rows of the touch screen capacitance matrix require being scanned; two rows or two columns can be scanned every time to obtain the capacitance difference value between the two rows or the two columns, or one row or one column can be scanned every time to obtain the capacitance difference value between the row or the column and a benchmark capacitance, and the obtained capacitance difference value data is processed. This processing method is complicated and has a large amount of computation.
Each of the above-mentioned methods discloses methods for overcoming LCM interferences and common mode interferences individually; however, there is no method capable of overcoming both LCM interferences and common mode interferences at present.